Lagoon City
Clear Sky Chart
History

This sumarizes the distribution of each different forecast outcome for the Lagoon City clear sky chart from 2005-11-05 to 2017-09-16.

This page is a summary of past forecasts. Even though it's based only on forecasts, some people use these pages as clue to a site's climate. But climate data based on actual observation should be preferred (if you can find it!).

Cloud, Transparency and Seeing forecasts are summarized individually. But because good observing conditions require a combination of minimum cloud cover, transparency and seeing, the individual forecast summaries can be difficult to interpret. The observing conditions section counts the combinations of conditions needed for common types of astronomical observation.

Observing Conditions

The following tables count the occurrence of the combinations of forecast and darkness conditions needed for different observations. Conditions are rated by by what percentage of the hours the observation would likely be attempted are usable.
Observation TypeMinimum conditions for hour to be usableOut of hours
Clear of CloudsTransparencySeeingSky Brightness
Planetary:50%(no limit)Average(no limit)Nighttime Hours
Deep Sky:70%Average(no limit)5.9Nighttime Hours
CCD Imaging:70%Below AveragePoor(no limit)Nighttime Hours

Percentages are of nighttime hours per month, or per year, when a particular observing conditions was met. Deep Sky percentages never exceed 50% because the moon is up half the time. Deep sky percentages are much lower for charts at high latitudes because of fewer dark hours in the summer.

Overall

PlanetaryData
Pts
Deep Sky
Max 60%
Data
Pts
Both Planetary and Deep Sky
Max 60%
Data
Pts
Either Planetary or Deep SkyData
Pts
CCD ImagingData
Pts
Night
37%
14738
13%
46624
9%
14705
41%
14705
18%
33374

By Month

MonthDays of MonthPlanetaryData
Pts
Deep Sky
Max 60%
Data
Pts
Both Planetary and Deep Sky
Max 60%
Data
Pts
Either Planetary or Deep SkyData
Pts
CCD ImagingData
Pts
January1st to 15thNight
16%
718
7%
2506
3%
716
22%
716
8%
2050
January16th to endNight
25%
768
9%
2499
6%
768
30%
768
9%
2008
February1st to 15thNight
23%
701
8%
2287
5%
701
27%
701
11%
1801
February16th to endNight
29%
631
12%
2030
7%
631
36%
631
16%
1490
March1st to 15thNight
31%
720
13%
1980
8%
720
35%
720
19%
1460
March16th to endNight
42%
768
20%
2112
13%
768
47%
768
28%
1414
April1st to 15thNight
35%
718
15%
1808
8%
718
39%
718
23%
1322
April16th to endNight
41%
561
19%
1641
11%
561
46%
561
24%
1117
May1st to 15thNight
53%
459
16%
1539
14%
459
56%
459
23%
996
May16th to endNight
56%
374
15%
1497
17%
374
62%
374
24%
841
June1st to 15thNight
48%
360
10%
1440
11%
360
54%
360
21%
875
June16th to endNight
58%
360
12%
1275
16%
360
61%
360
25%
777
July1st to 15thNight
67%
340
16%
1281
23%
340
71%
340
33%
671
July16th to endNight
63%
447
16%
1483
17%
419
65%
419
28%
859
August1st to 15thNight
65%
539
16%
1609
13%
536
67%
536
35%
946
August16th to endNight
60%
624
19%
1770
12%
624
64%
624
34%
1101
September1st to 15thNight
55%
720
16%
1800
9%
720
57%
720
32%
1211
September16th to endNight
53%
658
20%
1842
14%
658
57%
658
29%
1194
October1st to 15thNight
36%
660
15%
1980
14%
660
40%
660
18%
1436
October16th to endNight
21%
704
10%
2112
5%
704
28%
704
11%
1668
November1st to 15thNight
32%
700
15%
2405
14%
700
37%
700
16%
1706
November16th to endNight
22%
720
8%
2520
6%
720
26%
720
8%
2013
December1st to 15thNight
14%
720
4%
2520
2%
720
17%
720
6%
2133
December16th to endNight
13%
768
7%
2688
2%
768
19%
768
6%
2285

Individual Forecasts

The length of each colored bar in the "occurrence of each Forecast" column is proportional to the number of times the chart forecast that color. The percentages are of the total number of hours per month, or per year, with a particular forecast. The colors as the same as those used in clear sky charts.

Note: Transparency probabilities are only counted for those hours that have 30% or less cloud cover. Seeing probabilities are only counted for those hours that have 80% or less cloud cover. If that's too tricky, try Observing Conditions instead.

Overall

Occurrence of each ForecastData
Points
Cloud CoverDay
15%8%36%6%35%45%7%33%
48109
Night
16%9%47%6%3445%6%31%
46799
Cloud CoverDay
16%8%36%5%35%45%7%33%
48119
Night
16%10%47%5%3445%6%32%
46804
TransparencyDay
49%6%13%19%10%
47802
Night
52%5%12%18%10%
46624
SeeingDay
18%421%31%17%5%
5562
Night
20%5%26%31%13%1
14744

By Month

Percentage Cloud Cover NE (2006-)
Color Meanings:
Overcast 90% covered 80% covered 70% covered 60% covered 50% covered 40% covered 30% covered 20% covered 10% covered Clear
MonthDays in MonthOccurrence of each ForecastData
Points
January1st to 15thDay
17%13%6%9%7%44446%20%
1432
16th to endDay
14%16%5%10%7%45%45%5%19%
1722
February1st to 15thDay
12%14%6%13%8%345%36%20%
1575
16th to endDay
14%13%5%8%9%45%45%5%23%
1440
March1st to 15thDay
13%10%47%7%35%46%5%30%
1969
16th to endDay
14%8%35%5%3435%5%39%
2112
April1st to 15thDay
20%7%46%6%3434434%
2140
16th to endDay
17%7%345%23446%39%
2328
May1st to 15thDay
16%6%36%6%35%45%5%36%
2412
16th to endDay
12%5%25%5%35%5%5%8%42%
2618
June1st to 15thDay
17%7%26%5%24448%36%
2520
16th to endDay
13%425%5%35%5%6%10%36%
2679
July1st to 15thDay
8%4245%36%5%7%9%43%
2598
16th to endDay
9%425%5%36%6%6%10%38%
2580
August1st to 15thDay
10%5%25%4345%5%8%42%
2340
16th to endDay
10%5%245%35%5%6%8%42%
2420
September1st to 15thDay
16%6%246%3345%7%40%
2160
16th to endDay
14%6%25%5%34445%42%
1788
October1st to 15thDay
22%7%37%5%34446%31%
1650
16th to endDay
28%9%37%6%245%5%5%21%
1760
November1st to 15thDay
18%9%46%6%35%46%6%28%
1450
16th to endDay
22%14%5%7%6%35%5%6%6%18%
1440
December1st to 15thDay
18%18%6%10%7%35%345%14%
1440
16th to endDay
21%15%6%9%6%345%5%5%15%
1536
January1st to 15thNight
19%14%6%11%9%34445%17%
2506
16th to endNight
15%15%6%11%7%3445%5%18%
2499
February1st to 15thNight
12%15%6%11%8%46%445%20%
2285
16th to endNight
15%12%48%6%3445%6%27%
2030
March1st to 15thNight
17%10%46%5%35%43432%
1968
16th to endNight
16%7%36%423446%41%
2112
April1st to 15thNight
20%8%26%5%2435%5%32%
1808
16th to endNight
13%7%37%6%24447%38%
1641
May1st to 15thNight
16%6%25%434448%38%
1539
16th to endNight
10%424425%45%8%45%
1495
June1st to 15thNight
15%5%246%3445%8%39%
1440
16th to endNight
11%5%35%435%46%8%41%
1275
July1st to 15thNight
6%424435%447%52%
1359
16th to endNight
9%324435%47%8%45%
1585
August1st to 15thNight
6%4144345%6%8%48%
1620
16th to endNight
9%415%5%35%447%49%
1770
September1st to 15thNight
15%42442445%7%43%
1800
16th to endNight
14%6%245%33346%45%
1842
October1st to 15thNight
19%7%36%5%4446%5%31%
1980
16th to endNight
24%11%37%6%35%45%5%23%
2112
November1st to 15thNight
17%10%36%5%3445%7%31%
2405
16th to endNight
22%12%5%7%7%36%45%6%20%
2520
December1st to 15thNight
20%17%6%9%6%35%445%15%
2520
16th to endNight
21%17%7%10%8%34345%13%
2688

Percentage Cloud Cover SE (2006-)
Color Meanings:
Overcast 90% covered 80% covered 70% covered 60% covered 50% covered 40% covered 30% covered 20% covered 10% covered Clear
MonthDays in MonthOccurrence of each ForecastData
Points
January1st to 15thDay
17%14%6%9%8%34347%20%
1432
16th to endDay
14%15%6%10%7%35%35%6%19%
1722
February1st to 15thDay
12%14%7%13%7%34446%21%
1575
16th to endDay
14%13%5%9%7%5%5%45%5%23%
1440
March1st to 15thDay
14%11%37%7%35%45%5%30%
1980
16th to endDay
15%8%36%6%24446%38%
2111
April1st to 15thDay
20%8%46%5%34345%34%
2140
16th to endDay
18%8%34433446%39%
2328
May1st to 15thDay
16%7%35%6%35%5%5%5%36%
2412
16th to endDay
13%5%25%5%25%45%7%41%
2618
June1st to 15thDay
18%7%25%5%24449%35%
2520
16th to endDay
14%5%35%5%35%5%6%9%36%
2679
July1st to 15thDay
9%4235%35%6%6%9%42%
2598
16th to endDay
10%5%35%5%45%6%6%9%37%
2580
August1st to 15thDay
11%6%25%4345%6%9%41%
2340
16th to endDay
10%5%25%5%245%6%8%41%
2420
September1st to 15thDay
16%5%25%5%2445%7%40%
2160
16th to endDay
15%6%35%5%35%345%42%
1788
October1st to 15thDay
22%7%36%5%34446%31%
1650
16th to endDay
29%10%36%5%245%45%21%
1760
November1st to 15thDay
18%11%36%6%25%45%7%28%
1450
16th to endDay
22%14%5%7%6%25%5%5%6%18%
1440
December1st to 15thDay
18%18%6%11%6%35%445%15%
1440
16th to endDay
21%15%7%8%5%3446%5%16%
1536
January1st to 15thNight
18%15%6%11%9%3344417%
2506
16th to endNight
14%16%6%10%7%3445%6%19%
2499
February1st to 15thNight
12%15%7%10%8%35%445%20%
2278
16th to endNight
16%12%48%6%25%45%6%27%
2030
March1st to 15thNight
18%11%46%435%435%32%
1980
16th to endNight
16%7%36%42335%6%41%
2112
April1st to 15thNight
21%8%35%5%34346%32%
1808
16th to endNight
14%7%47%5%33447%38%
1641
May1st to 15thNight
17%6%25%5%34447%38%
1539
16th to endNight
11%424325%45%8%45%
1495
June1st to 15thNight
15%5%245%345%5%7%39%
1440
16th to endNight
11%5%34425%45%8%42%
1275
July1st to 15thNight
7%324435%447%53%
1359
16th to endNight
9%425%335%46%9%45%
1585
August1st to 15thNight
7%4144345%6%8%48%
1620
16th to endNight
9%4145%3445%7%48%
1770
September1st to 15thNight
15%5%25%33445%8%43%
1800
16th to endNight
14%6%245%23347%45%
1842
October1st to 15thNight
20%7%36%5%3345%6%31%
1980
16th to endNight
26%9%36%5%34445%24%
2112
November1st to 15thNight
18%10%45%43445%7%31%
2405
16th to endNight
22%12%5%7%6%35%45%6%20%
2520
December1st to 15thNight
21%17%6%9%6%35%45%5%15%
2520
16th to endNight
21%17%7%11%7%3334414%
2688

Transparency (when cloud cover <= 30%)
Color Meanings:
Too cloudy to forecast Poor Below Average Average Above average Transparent
MonthDays in MonthOccurrence of each ForecastData
Points
January1st to 15thDay
65%6%11%11%4
1433
16th to endDay
64%5%10%10%7%
1722
February1st to 15thDay
64%412%14%3
1577
16th to endDay
61%412%13%8%
1440
March1st to 15thDay
52%5%16%17%7%
1980
16th to endDay
45%311%18%17%2
2112
April1st to 15thDay
51%410%19%13%
2140
16th to endDay
45%49%22%15%1
2328
May1st to 15thDay
47%411%21%13%1
2412
16th to endDay
39%5%14%23%14%2
2622
June1st to 15thDay
44%5%14%24%10%
2520
16th to endDay
40%8%16%21%12%
2679
July1st to 15thDay
31%8%15%27%14%1
2447
16th to endDay
39%7%14%26%10%1
2419
August1st to 15thDay
36%7%18%23%12%1
2327
16th to endDay
36%7%16%27%10%1
2420
September1st to 15thDay
42%6%14%26%9%
2160
16th to endDay
44%5%12%28%8%
1788
October1st to 15thDay
53%5%11%19%9%
1650
16th to endDay
61%6%13%12%4
1760
November1st to 15thDay
55%6%14%15%7%
1450
16th to endDay
65%8%11%10%3
1440
December1st to 15thDay
72%5%13%7%1
1440
16th to endDay
69%7%10%9%3
1536
January1st to 15thNight
69%410%10%3
2506
16th to endNight
66%6%9%12%5%
2499
February1st to 15thNight
65%411%14%3
2287
16th to endNight
55%5%13%17%7%
2030
March1st to 15thNight
54%412%19%8%
1980
16th to endNight
43%411%22%16%1
2112
April1st to 15thNight
51%39%19%13%1
1808
16th to endNight
45%5%9%17%19%2
1641
May1st to 15thNight
44%412%17%16%3
1539
16th to endNight
36%5%14%25%16%1
1497
June1st to 15thNight
42%5%12%23%15%
1440
16th to endNight
38%6%15%23%15%
1275
July1st to 15thNight
29%5%12%30%21%
1281
16th to endNight
34%6%12%31%14%
1483
August1st to 15thNight
30%7%20%26%14%
1609
16th to endNight
33%7%15%27%15%1
1770
September1st to 15thNight
38%6%15%25%12%1
1800
16th to endNight
39%5%12%30%11%
1842
October1st to 15thNight
52%6%9%20%10%
1980
16th to endNight
61%6%10%13%6%
2112
November1st to 15thNight
52%6%13%17%8%1
2405
16th to endNight
64%7%12%11%2
2520
December1st to 15thNight
70%7%11%8%2
2520
16th to endNight
73%5%7%8%4
2688

Seeing (when cloud cover <= 80%)
Color Meanings:
Too cloudy to forecast Bad 1/5 Poor 2/5 Average 3/5 Good 4/5 Excellent 5/5
MonthDays in MonthOccurrence of each ForecastData
Points
January1st to 15thDay
20%13%45%15%6%
60
16th to endDay
35%230%24%7%
95
February1st to 15thDay
23%10%37%28%
90
16th to endDay
29%430%34%2
93
March1st to 15thDay
20%8%28%33%8%
270
16th to endDay
24%225%30%13%2
288
April1st to 15thDay
21%229%34%10%1
270
16th to endDay
19%325%29%16%5%
270
May1st to 15thDay
24%120%29%16%7%
288
16th to endDay
16%119%38%18%6%
331
June1st to 15thDay
21%117%34%20%4
315
16th to endDay
14%221%38%19%4
474
July1st to 15thDay
10%16%39%24%8%
381
16th to endDay
7%119%37%26%7%
326
August1st to 15thDay
12%211%34%28%10%
313
16th to endDay
13%314%24%30%13%
332
September1st to 15thDay
11%415%29%23%15%
315
16th to endDay
18%415%30%20%10%
254
October1st to 15thDay
21%423%30%14%5%
255
16th to endDay
29%13%28%21%6%
272
November1st to 15thDay
15%6%34%31%9%2
86
16th to endDay
36%10%25%26%1
60
December1st to 15thDay
21%21%30%21%31
60
16th to endDay
32%20%39%7%
64
January1st to 15thNight
25%9%35%20%6%1
720
16th to endNight
22%6%28%33%7%1
768
February1st to 15thNight
20%436%31%6%
704
16th to endNight
22%432%31%7%
631
March1st to 15thNight
22%5%32%33%5%
720
16th to endNight
20%226%34%14%1
768
April1st to 15thNight
25%327%35%7%
718
16th to endNight
16%328%34%14%1
561
May1st to 15thNight
20%217%36%19%2
459
16th to endNight
12%319%40%23%
375
June1st to 15thNight
17%221%39%17%1
360
16th to endNight
11%317%43%23%1
360
July1st to 15thNight
8%216%45%24%2
340
16th to endNight
10%117%41%27%1
447
August1st to 15thNight
8%16%41%29%3
539
16th to endNight
10%217%34%30%3
624
September1st to 15thNight
17%317%30%22%7%
720
16th to endNight
18%317%33%20%6%
658
October1st to 15thNight
22%6%27%28%12%2
660
16th to endNight
29%11%31%21%5%
704
November1st to 15thNight
22%9%30%25%11%1
700
16th to endNight
27%13%29%22%7%
720
December1st to 15thNight
29%14%33%18%3
720
16th to endNight
28%8%36%21%31
768
Page generated at 2017-09-16 17:06:59. Version ac04

Copyright 2017 A. Danko


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